The present invention generally relates to an apparatus for automatically dispensing granular material, and more particularly to a hopper feed regulating device for controlling the supply of feed to livestock via a feed hopper.
In order for certain domesticated animals to efficiently gain weight, it is essential to provide them with adequate feed at all times. Accordingly, the amount of feed made available to the animals must be repeatedly and accurately adjusted depending on the growth of the animals.
One prior art attempt at maintaining the optimum level of feed to poultry comprises using a feed cart supported on an overhead rail to transport feed through a chicken house. The cart is manually rolled along the rail to feed stations throughout the house while feed is shoveled from the cart onto the floor level.
With the advent of automated chicken houses, feed may be automatically conveyed from a central hopper outside the house to feed receptacles distributed throughout the house without manual labor. In order to provide feed on an xe2x80x9cas neededxe2x80x9d basis, a multiplicity of feed pans or stations, which are typically hung from a ceiling or upper support, are arranged in rows along the length of the chicken coop and provided with feed when empty.
The feed pans are each connected to a conduit that, using an auger arrangement, delivers feed to the pans when an empty condition is sensed at the feed pans. The conduit is supplied from an intermediate hopper, positioned at one end of the chicken coop. When the level of feed in the intermediate hopper drops to a predetermined level, it is then re-supplied with feed from a main feed hopper, positioned outside of the chicken coop.
Contact switches are generally used both to sense the level of feed in the feed pans and to signal for the supply of feed to the feed pans from the intermediate hopper as needed. Additionally, a contact switching arrangement is provided to sense when feed to the intermediate hopper is needed from the primary feed hopper or silo.
Referring to FIG. 1, a known contact switch arrangement or flap switch for use in the intermediate hopper is generally illustrated at 11 and comprises a hinged flap 13 which pivots back and forth along the directions of arrow A so as to make a depressible contact switch 15 turn on and off. In this arrangement, the contact switch 15 is off when depressed and is on when released. In the on position, the contact switch 15 signals a feed motor to supply feed to the hopper.
Typically, the switch arrangement 11 is positioned in the hopper at a height that equals the desired level of feed when the hopper is full. Positioned adjacent the hinge flap 13 is a feed supply conduit 17 which pours feed B at the hinge flap 13. When the supply of feed to the hopper reaches the desired level in the hopper, the feed piles up in front of the flap 13 so that the weight of the pile pivots the hinge flap 13 back against the contact switch 15, thereby pushing the switch 15 to the off position and cutting off the supply of feed. As the level of feed falls, the weight of the pile of feed at the hinge flap 13 is reduced causing the flap 13 to spring forward and release contact switch 15 to the on position, as shown in FIG. 1, so as to signal for additional feed.
While operationally quite efficient when used at the feed pans, the flap switch 11 tends to hang-up when used in the intermediate hopper. Constant exposure to feed causes grease to build up on the hinge flap 13, making it difficult to spring back and release the contact switch 15 to the on position. As a result, when the flap switch 11 fails, the intermediate hopper is not supplied with feed from the main hopper and the plurality of feed pans become depleted of feed.
If, for example, the flap switch 11 hangs up in the middle of the night, the chickens may go without feed until the next morning. By then, the chickens are so hungry that when they are finally fed, they eat so quickly that the feed travels right through the animals without being fully digested. This results in an unacceptable conversion of feed to body weight.
A further deficiency of the known flap switch arrangement is its tendency to switch on and off or xe2x80x9cbouncexe2x80x9d at the cut off rather than letting the motor run uninterrupted until the level of feed in the hopper reaches the desired level.
A prior attempt at alleviating the deficiencies of the flap switch include Harkins, U.S. Pat. No. 5,389,753, which discloses a feed control switch for controlling the supply of feed to a hopper without the need to contact the feed.
Referring to FIG. 2, the Harkins feed control switch for supplying feed to an intermediate hopper is generally illustrated at 21. The apparatus comprises a first tubular member 23 having a hanger 25 from which the Harkins feed control switch is suspended and a second tubular member 29 slidably moveable relative to the first member 23, the second member 29 having a suspender 31 from which an intermediate feed hopper is suspended. A spring biasing arrangement 37, such as a helical coil compression spring, is provided for pulling the first and second members 23 and 29 together at a predetermined spring bias strength and a switch contact surface 28 is provided at the first member 23. An on/off switch 34 is positioned adjacent to the switch contact surface 28 and at the second member 29 so as to move with the second member, the switch 34 being in an off position when the switch 34 is at an extended position and being in an on position when the switch 34 is at a depressed position.
When the weight of feed in the hopper exceeds the predetermined spring bias strength of the spring biasing arrangement, the second member 29, which carries the switch 34, pulls away from the first member 23 causing the switch 34 to move away from and disengage the switch contact surface 28 at the first member 23. As a result, the switch 34 moves to the extended and off position, which signals a feed motor to terminate the supply of feed to be conveyed to the intermediate feed hopper. However, as feed is removed from the feed hopper to feed the chickens, at some point the predetermined spring bias strength overcomes the weight of the feed in the hopper and the second member 29 is pulled towards the first member 23 causing the switch to engage the contact surface 28 so that the switch 34 moves to the depressed and on position, which signals for the supply of feed to the feed hopper.
While the Harkins feed control switch attempts to resolve the deficiencies of the flap switch, it still suffers from similar deficiencies. For example, the Harkins switch comprises an open tubular design that exposes both the spring biasing arrangement as well as the tubular members to dust and other airborne particles. Accordingly, constant exposure may cause a build up of grime that interferes with operation of the control switch apparatus.
A further deficiency of the Harkins feed control switch is its tendency to switch on and off rapidly causing unnecessary wear on the feed motor. The rapid switching is caused by the relatively small weight differential required in the intermediate feed hopper to trigger and untrigger the switch. The on and off repetition may result in failure of the motor, which not only results in inefficient feed conversion but also may require a costly replacement of the feed motor.
Therefore, there is a need in the art for an apparatus for controlling the supply of feed to a feed hopper that is not easily exposed to dust and other airborne particles. There is also a need for such an apparatus that may be implemented without causing unnecessary wear on a feed supply motor. There is still an additional need for an apparatus that is easily adjustable for different types of feed and feed hoppers having different weights and densities.
The present invention satisfies the above described needs by providing an apparatus for automatically regulating the supply of feed to a feed hopper. In general, the hopper feed regulator is suspended between a chicken house ceiling and an intermediate feed hopper. The regulator has a first upper hanger attached to the ceiling and a second lower hanger attached to the feed hopper. A bias means, such as a helical spring, is disposed between the upper and lower hangers. The upper hanger is rigidly fixed to the regulator casing, whereas the lower hanger is configured to move relative to the upper hanger in an axial direction and against the force of the spring. In addition, the regulator, which is connected to a motor, has an on/off switch assembly that is activated by the relative movement of the hangers. When the switch is turned on, the motor is activated and feed is supplied to the feed hopper. As the weight of the feed hopper decreases, the weight of the hopper causes relative movement of the hangers against the force of the spring. Once the hangers have moved past a threshold point, the switch is turned off and no further feed is supplied to the feed hopper.
More particularly, the spring is positioned vertically and is disposed between the upper and lower hangers to support the feed hopper with a predetermined amount of bias tension. The top end of the spring is connected to a lower hanger that extends through the bias means. The lower hanger comes out the bottom end of the spring and is used to suspend the feed hopper. Accordingly, the weight of the feed hopper compresses the spring from the top down. In order to maintain the spring in the proper vertical alignment, the spring is enclosed in a sleeve that is approximately the diameter of the spring. The sleeve is attached to the upper hanger so that the relative movement between the upper hanger and the lower hanger varies the tension on the spring.
An elongated cam is connected to the top end of the spring and lower hanger and thus moves with the top end of the spring and lower hanger. The cam extends through a vertical slot in the sleeve and gradually descends outwardly from the sleeve. Accordingly, the bottom end of the cam is further from the spring than the top end of the cam.
A switch assembly is fixed to the regulator casing adjacent to the first cam with the switch contact, or button, facing the cam. The switch includes an elongated lever that extends over the switch contact and parallel with the sleeve. The bottom end of the lever is fixed to the switch below the switch contact. The top end of the lever extends beyond the switch contact. The top end of the lever includes a wheel assembly that contacts and rolls along the cam.
The device described above functions in the following manner. As the feed contained in the feed hopper empties, the tension on the spring decreases causing the top end of the spring and the connected cam to rise. Because the cam extends away from the spring, cam action causes the wheel assembly to push away from the spring thereby causing the lever to engage the switch contact, (i.e., depress the switch button). The engaged condition of the switch contact causes a motor to supply additional feed into the feed hopper. As the weight increases in the feed hopper, the top of the spring along with the cam descends, which causes the wheel assembly to move along the cam surface and away from the switch contact. Once the lever has moved far enough away from the switch contact, the switch turns off and the motor stops conveying additional feed to the feed hopper.